The present invention relates to the photographing of motion picture films where it is desired to obtain both two dimensional images of a scene and also information about the relative distances of objects in the scene from the camera position. More particularly the invention relates to a motion picture camera incorporating two taking lenses, one of which images onto film through a shutter and film advance mechanism to capture a sequence of successive photographic images, and the other of which images onto a digital sensor containing a plurality of photodetectors arranged in a matrix. A means is provided to synchronize the taking of the photographic and digital images. The digital sensor is interfaced to a storage device and this storage device captures the output of the sensor photosites as a function of time. Subsequently, the film is processed and then scanned using a film scanner. The digital form of the film image is then compared to the sensor data using a software program, and using the relative positions of corresponding points between the digitized photographic image and the sensor data, the distance of objects from the camera to each point in the scene may be determined.
The use of digital sensors for the capture of image sequences is well known. However, even with current advances in technology a digital sensor system lacks the spatial and color resolution to compete with photographic film in terms of image quality. When a previously photographed motion picture film sequence is combined with computer generated images, a three dimensional model must be constructed for the original scene so that the computer generated image is of the correct size and perspective in order to match the action in the original scene. This may be accomplished by very careful measurement of the original scene when it is photographed, but this process is prone to error and omissions. Various types of range measuring or scanning devices have been proposed, but these are all limited in measurement accuracy and require careful setup and calibration.
A convenient method for obtaining this information is to use stereoscopic image pairs. Assuming that the relative alignments of the two image pairs are known, it is possible to determine the distance to various points in the scene by determining the disparity or coordinate difference between corresponding points in each image of the pair.
Using strictly film photography it is necessary to take two pictures at every time instant that is required for the motion picture film sequence, and this results in twice as much film being exposed as would be required when distance information is not required. The size and weight of this film is inconvenient and costly. However, for use in motion picture films the image quality of a photograph is essential. It would be an improvement to combine the image quality of the photographic process with a digital sensor that would allow determination of distance without the use of range scanners or other measuring devices.
It is an object of the present invention to provide a photographic quality image sequence accompanied by sufficient digital data that a three dimensional model of the scene may be constructed. It is another objective of this invention to permit the capture of stereoscopic image pairs without requiring the use of two film cameras or any other system that makes two photographic images at every time instant in order to create a sequence of stereoscopic image pairs.
It is another object of the present invention to capture the second image of the stereoscopic image pair sequence using a digital image sensor and storage device. Said device may capture consecutive frames of image data using a plurality of sensors arranged in a matrix, and such image data frames may be stored within the camera in a semiconductor or disk memory.